Our body perfectly functions only if fully aligned. There is no other way! The quality of our life strictly depends on the spinal alignment, so our posture is a key element for being in a good state of health.
Every single moment, our body fights an invisible force to stay upright: the gravity. The brain continuously works to find our body’s position in the space, i.e. the posture. Roger Sperry (Nobel Prize in Physiology and Medicine in 1981) discovered that 90% of the
brain’s activity is used to balance our body within the gravitational field of earth. If our body is mechanically distorted, it will affect the other 10% of the brain’s activity, which controls all the other body functions such as breathing, digestion and cognition .
The pillar of our posture is the spine (Figure 1), that is held in place by the soft tissues of the body, i.e. muscles, tendons, ligaments and fascia. Take all the soft tissues away and the bones would pile on the floor, as they do not interlock or stack in any kind of stable way.
The position of the bones depends on the tensional balance among soft tissue elements. In order to guarantee body balance, the myofascia (a thin layer covering and connecting muscles) in a human body has intrinsic tone and is never completely lax (stress/strain can never reach zero): the integrity lies in the balance of tension, named tensegrity. Forces are distributed throughout the system rather than locally concentrated and the musculoskeletal system therefore functions as a single unit . As gravitational forces act upon our bodies when we are upright, various groups of musculature work synergistically so that we can stay erect (Figure 2).
As gravity acts on all parts of the body, one’s entire weight can be considered as concentrated at a point where the gravitational pull on one side of the body is equal to the pull on the other side. This point is the body’s center of gravity, and it constitutes the exact center of body mass (Figure 3). When the center of gravity is above the base of support and the pull of gravity is successfully resisted by the supporting members, an equilibrium of forces or a state of balance is reached and no motion occurs . The line of gravity is considered to run anterior to L4-5, but it moves naturally with changes in spinal alignment. In particular, as inclination of the trunk increases, the gravity line moves further anterior, with muscles of the back that must counteract the change in the center of gravity , with following back pain .
But where do our postural problems originate? Our body is a complex but perfect system, with many inputs and outputs. The posture is an output of this system, with inputs coming from vestibular, visual and somatosensory systems [6,7], with this last one including proprioception (Figure 4). Proprioception is the awareness of the position of one’s body, possible with stimulus coming from nerves throughout our entire body. Occlusion is part of the proprioceptive inputs.
Under the hypothesis of sensory reweighting, every input has a weight when processed by our brain. When a certain input is distorted or missing, the system rebalances the weight of other inputs or even suppresses some of them when they are in conflict, so that the body is always in the most stable position [8,9,10]. This has been proved by many studies, with body posture that changes according to different vision stimulus  or different occlusion contacts [12,13,14]. However, occlusion is just the consequence and adaptation of the cranial situation . See in Figure 5 the direct relationship between cranial distortions and occlusion.
The maxilla remodels according to forces coming from the tongue and the teeth in contact. When these forces are missing, the maxilla remodels down and backward, elongating the facial shape. As a consequence, the mandible swings back and the body reacts with a forward head posture , as can be seen in Figure 6.
With a forward head posture, increasing the kyphotic and then lordotic curves is the only way the body has to find the center of gravity [17,18]. With an increased lordosis, also the pelvis rotates forward, with consequences until the feet . Figure 7 shows different body postures according to different classes of malocclusion: notice the different head posture and following compensatory mechanisms to find the center of gravity.
In the presence of cranial distortions, the mandible deviates to one side as a consequence of the occipital bone position, while the maxilla rotates to the other side, mapping the sphenoid bone. As a consequence, facial features are asymmetrical and the head is tilted on one side . The shoulder where the head is tilted lifts up to level the eyes. Then, the body has to compensate, creating a scoliotic curve [20,21]. As a consequence, the hips are not aligned, giving the impression of a leg shorter than the other. However, the real length of the legs is the same, they are just asymmetrically aligned, as Figure 8 highlights.
If kyphosis, lordosis and pelvis anteversion are adaptation of the body in the sagittal plane, tilted head, unlevel shoulders, scoliosis, unlevel hips are adapatation on the frontal plane. However, we still miss one plane: the transversal or horizontal plane (Figure 9).
In the presence of cranial distortion, the skull is twisted, with sphenoid and occipital bones in opposite rotation. Then, this is also reflected in all the spine: indeed, in the presence of scoliosis there is also vertebrae rotation on the transversal plane [22,23], together with rotation of the pelvis (Figure 10) .
Our body better functions when it is aligned, on all the three planes. If not aligned, the body suffers, full stop! For every centimeter that the head is held forward (rather than balanced properly over the body), it gains about 2 kg of weight, with muscles of the back and neck that have to work much harder . Here is the link between forward head posture and reduced neck mobility , neck pain [27,28], migraine  and tension-type headache  and the link between scoliosis and pain in several anatomical locations [30,31,32].
But in all of this, we still miss the bigger pictures. What happens when there is chronic tension in certain muscles? What happens when spine is not aligned and vertebrae are dislocated or subluxated? In our body we have blood vessels, nerves, glands, organs that can be compressed by either muscles that are overtightened or by vertebrae misalignment (Figure 11).
Think for example about large blood vessels going to the brain that can be compressed by neck muscle tension (Figure 12) [34,35], arteries that can be compressed by vertebral rotation (Figure 13) [36,37,38], the spinal cord that can be compressed by vertebral dislocation or subluxation (Figure 14) , lungs that have decreased capacity with an increased kyphosis [40,41], or about duodenum compression as a consequences of increasing lordosis or scoliosis .
Consequences are disrupting. The restriction in blood supply to tissues is called ischemia: this leads to insufficiency of oxygen (hypoxia), reduced availability of nutrients and inadequate removal of metabolites. This damages the tissues and an inflammatory response is activated. Inflammation is a defense mechanism in the body in which the immune system clears out necrotic cells and damaged tissues. However, if the blood vessels compression is chronic, then inflammation becomes chronic too, with following fibrosis and calcification.
Current medicine considers an autoimmune disease, e.g. Multiple Sclerosis, as a condition in which the immune system mistakenly attacks the body, causing an inflammation [44,45]. However, are we sure that the inflammation is the consequence and not the cause of the disease? After all, Multiple Sclerosis has been linked to CCSVI (chronic cerebrospinal venous insufficiency) [46,47], that is a reduced blood flow from the brain and spinal cord due to narrowing of veins in the neck.
Furthermore, many other diseases have blood flow that plays a major role. To cite some:
- The subcutaneous blood flow in the scalp of patients with early male pattern baldness is much lower than the values found in the normal individuals , with lower oxygen partial pressure (meaning microvascular insufficiency and hypoxia) .
- Severity of schizofrenia can be predicted by meaning of blood flow within the brain .
- People with stuttering have a lower regional cerebral blood flow in Broca’s area .
- Patients with mild cognitive impairment, dementia and Alzheimer’s disease have a reduced cerebral blood flow [52,53], with the entire brain that is degraded, resulting in tissue loss (Figure 15).
Current medicine still focuses too much on isolated parts of the body, lacking the consequences that these parts can have in distal locations. Posture has an important role in body’s health that can be truly understood only in a holistic approach. Spinal posture is what determines the dependence in activities of daily living  and our life satisfaction  when we become older. Spinal posture is also what predicts our mortality  and after having read this page we should all know why: alignment is the key for body’s health, do not forget it!
 Fernández-de-Las-Peñas, C., C. Alonso-Blanco, and J. C. Miangolarra. “Myofascial trigger points in subjects presenting with mechanical neck pain: a blinded, controlled study.” Manual therapy 12.1 (2007): 29-33.
 Fernández‐de‐las‐Peñas, César, et al. “Trigger Points in the Suboccipital Muscles and Forward Head Posture in Tension‐Type Headache.” Headache: The Journal of Head and Face Pain 46.3 (2006): 454-460.
 Gray, Sarah Delcenia, Erik Carlsson, and Norman C. Staub. “Site of increased vascular resistance during isometric muscle contraction.” American Journal of Physiology–Legacy Content213.3 (1967): 683-689.
 Mitchell, Jeanette, et al. “Is cervical spine rotation, as used in the standard vertebrobasilar insufficiency test, associated with a measureable change in intracranial vertebral artery blood flow?.” Manual Therapy 9.4 (2004): 220-227.
 Mitchell, Jeanette. “Vertebral artery blood flow velocity changes associated with cervical spine rotation: a meta-analysis of the evidence with implications for professional practice.” Journal of Manual & Manipulative Therapy 17.1 (2009): 46-57.
 Goldman, Boris E., David M. Fisher, and Steven L. Ringler. “Transcutaneous PO2 of the scalp in male pattern baldness: a new piece to the puzzle.” Plastic and reconstructive surgery97.6 (1996): 1109-16.
 Kamitani, Kojiro, et al. “Spinal posture in the sagittal plane is associated with future dependence in activities of daily living: a community-based cohort study of older adults in Japan.” Journals of Gerontology Series A: Biomedical Sciences and Medical Sciences 68.7 (2013): 869-875.
 Takahashi, Toshiaki, et al. “Trunk deformity is associated with a reduction in outdoor activities of daily living and life satisfaction in community-dwelling older people.” Osteoporosis International 16.3 (2005): 273-279.
 Kado, Deborah M., et al. “Hyperkyphotic posture predicts mortality in older community‐dwelling men and women: a prospective study.” Journal of the American Geriatrics Society52.10 (2004): 1662-1667.